Anchors for securing a fastener to a wall are known in the art. For example, some anchors are configured to extend completely through a wall and expand on the opposite side of the wall to prevent pull-out. These types of anchors are particularly useful for drywall and relatively thick-walled applications, but often prove ineffective for relatively thin-walled applications, such as molded plastic components.
For molded plastic components, anchors are not commonly used. Typically, fastener-connections are made in molded plastic components by screwing the fastener directly into the wall of the component without the use of an anchor. In some instances, an internally threaded hole can be formed in the plastic component for threadably engaging a fastener. More common, however, the component does not include a hole and the fastener is forcibly threaded into the solid wall of the component. In such anchorless applications, engagement between fasteners and the component wall provides some fastener pull-out resistance. However, such pull-out resistance is relatively low, for example, between about 60 and 70 pounds in some applications depending on the material and wall thickness of the component. Further, some anchorless applications, particularly those involving plastic components, require a boss or other fastener receiving feature with a relatively thick wall to provide sufficient engagement with the threads of the fastener. Thicker walls are often undesirable in plastic components as they add to the weight and manufacturing cost of the component. Additionally, for plastic components, fastener-component connections are prone to over-tightening during assembly, which can strip the threads formed in the component.
To increase the strength of anchorless connections, some conventional techniques include extending a fastener through both sides of a component, and securing a nut to the fastener to retain the fastener in place. Such “nut-and-bolt” connections may provide a high strength alternative to some anchorless connections. However, this type of “nut-and-bolt” connection is undesirable in applications requiring the absence of fastening features on one side of a component.